docs: def _get_path_scaling(self, C, dists, mag):
          """
          Returns the path scaling term given by equation (3)
          """
          rval = np.sqrt((dists.rjb ** 2.0) + (C["h"] ** 2.0))
          scaling = (C["c1"] + C["c2"] * (mag - self.CONSTS["Mref"])) *\
              np.log(rval / self.CONSTS["Rref"])
          return scaling + ((C["c3"] + C["Dc3"]) * (rval - self.CONSTS["Rref"]))